这道题正确答案是 B， 我一直觉得是D, 不是特别明白 B 答案为什么 说as effectively as sea snakes can? One such adaptation is the closer proximity of the terrestrial snake's heart to its head, which helps to ensure circulation to the brain, regardless of the snake's orientation in space. The heart of sea snakes can be located near the middle of the body, a position that minimizes the work entailed in circulating blood to both extremities. In arboreal snakes, however, which dwell in trees and often assume a vertical posture, the average distance from the heart to the head can be as little as 15 percent of overall body length. Such a location requires that blood circulated to the tail of the snake travel a greater distance back to the heart, a problem solved by another adaptation. 20. It can be inferred from the passage that which of the following is true of species of terrestrial snakes that often need to assume a vertical posture? (A) They are more likely to be susceptible to circulatory failure in vertical postures than are sea snakes. (B) Their hearts are less likely to be located at the midpoint of their bodies than is the case with sea snakes. (c) they cannot counteract the pooling of blood in lower regions of their bodies as effectively as sea snakes can. (d) the blood pressure at their midpoint decreases significantly when they are titled with their heads up.

If 500 is the mutiple of 100 that is closest to x and 400 is the multiple of 100 that is closest to y，which multiple of 100 is closest to x+y？ （1）x小于500 （2）y小于400

老师 32题不懂怎么解，都是看过答案解释还没懂的！

老师28题解答这里怎么是60的12次方，5的1次方？怎么化简化的？

老师，这道题做错了，不会，怎么解啊？谢谢！

May老师这道OG上的题没懂，即使看了下面的解释。谢谢哦！

求may老师解答

求may老师解答

求may老师解答

求may老师解答

求may老师解答